arXiv:cond-mat/0606291 · Physical Review B
Phase transition and phase diagram at a general filling in the spinless one-dimensional Holstein model
Sanjoy Datta, Sudhakar Yarlagadda
Abstract
We derive the Luttinger liquid to charge density wave (CDW) transition condition, exact to second order in a blocked perturbative approach, for the spinless one-dimensional Holstein model in the adiabatic regime. The small parameter is the ratio of the electron-phonon coupling $g$ and the adiabaticity parameter $t∕{\ensuremath{\omega}}_{0}$. Here we correct the mean-field criterion for Peierls instability, by replacing the static noninteracting susceptibility at twice the Fermi momentum ${\ensuremath{\chi}}_{0}(2{k}_{F},0)$ with the dynamic one, and get $1+2{g}^{2}{\ensuremath{\omega}}_{0}{\ensuremath{\chi}}_{0}(2{k}_{F},{\ensuremath{\omega}}_{0})=0$. At non-half-filling, we present the phase diagram showing the surprising result that the CDW occurs in a more restricted region of the two-parameter (${g}^{2}{\ensuremath{\omega}}_{0}∕t$ and $t∕{\ensuremath{\omega}}_{0}$) space than at half-filling.